SUBSTRATE FOR EPITAXIAL GROWTH, PROCESS FOR PRODUCING GAN-BASE SEMICONDUCTOR FILM, GAN-BASE SEMICONDUCTOR FILM, PROCESS FOR PRODUCING GAN-BASE SEMICONDUCTOR LUMINESCENT ELEMENT, AND GAN-BASE SEMICONDUCTOR LUMINESCENT ELEMENT

摘要

Disclosed is a substrate for epitaxial growth, comprising a single crystal part of a material different from a GaN-base semiconductor at least in a surface layer part. A concave and convex surface, which comprises a plurality of convexes arranged so that each convex has three most neighbouring other convexes in directions different from each other by 120 degrees, and a plurality of growth spaces each surrounded by six convexes described above, is provided as a surface for epitaxial growth. The single crystal part is exposed at least on the growth spaces, whereby a GaN-base semiconductor crystal of which the c axis is oriented from the growth spaces can be grown.